The co-combustion of biomass and semi-coke is considered to be a potential way to solve a large number of air pollution-relatedproblems such as carbon emissions, NOx and SO2. The air-staged combustion characteristics of semi-coke, mixture of semi-coke and biomass were studied by thermogravimetric experiment and drop tube furnace experiment respectively. The effects of blending ratio on ignitiontemperature, burnout temperature, slagging characteristics, fouling characteristics and combustion characteristic index of mixed fuel wereanalyzed, and the suitable air-staged combustion ratio, optimal combustion temperature and optimal blending ratio were determined. Theresults show that the ignition point of the mixed fuel is effectively reduced after co-firing biomass, and the ignition point is reduced from474 ℃ to 300 ℃ . The burnout temperature is slightly reduced after co-firing biomass. The combustion characteristic index is not significantly improved by the combustion of carbon mixed biomass. The combustion of biomass mixed with carbon powder has a tendency of highash deposition and a small tendency of slagging. The outlet NOx mass concentration and outlet SO2 mass concentration after co-firing biomass at different temperatures are lower than those before co-firing. Compared with those before co-firing, the mass concentration of outletNOx and SO2at 1 200 ℃ decreases significantly, reaching by 87.27 % and 80.2 % respectively. Based on comprehensive export parameters such as NOx, the optimal biomass mass fraction is 30% ~40%, and the optimal combustion temperature range is 1 200~1 300 ℃ under the condition of no air classification. The initial NOx emission of biomass with a mass fraction of 30% changes gently with temperatureduring staged combustion, showing good stability. The outlet NOx mass concentration is the lowest, all below 125 mg/ m3. The research conclusions can provide some technical support for the equipment operation of organic solid waste incineration disposal and the organizational regulation of related combustion conditions.